Final answer:
A patent is a legal instrument that establishes property rights for an inventor, serving as a government-enforced barrier to entry in a market.
Step-by-step explanation:
A patent is a legal device for creating property rights for an inventor. It grants the patent holder the exclusive legal right to make, use, or sell their invention for a limited period, typically 20 years. This grant is a government-enforced barrier to entry, meaning that competitors cannot legally enter the market with the same or a substantially similar product or process that the patent covers.
Patents are critical in encouraging innovation by allowing inventors the opportunity to recoup the costs associated with research and development. Without such protections, competitors might easily copy and profit from others' ideas, diminishing the incentive for the original inventors to invest time and resources into new discoveries.